1. Technical Field
The present invention relates to a knee protection airbag apparatus, in which an inflator has a generally circular columnar outer shape, a bolt is arranged to protrude from the inflator in a direction perpendicular to an axial direction of the inflator, and the inflator is attached to a case by protruding the bolt from the case and then fastening a nut to the bolt.
2. Related Art
Patent Document 1 discloses a knee protection airbag apparatus in which an inflator is attached to a case using a retainer. The inflator is attached to the case by protruding a bolt, which is arranged on the retainer with the inflator retained therein, from the case and then fastening a nut to the bolt. According to the knee protection airbag apparatus, in a side wall of a peripheral wall portion of the case, which is arranged on a connection port portion side of the inflator, an connector opening is formed to expose the connection port portion therethrough so that a connector can be connected to the connection port portion in a state where the inflator has been attached to the case, and on the peripheral edge of the connector opening, a protruding piece is formed to partially protrude from the peripheral edge of the connector opening. The protruding piece is provided to prevent the connection port portion side of the inflator from being protruded from the case upon operation of the inflator, i.e., to prevent the inflator from being fallen out through the connector opening. Also, according to the knee protection airbag apparatus, a protrusion is formed to protrude toward the inflator in a part of a bottom wall portion of the case near to a side wall having the protruding piece, and the protruding piece is configured to press an end surface on a peripheral edge of the connection port portion of the inflator when the inflator is abutted against the protrusion.
Patent Document 1: JP-A-2013-071567
However, according to the knee protection airbag apparatus, an outer peripheral surface of the inflator is not always abutted against the protrusion, but the outer peripheral surface of the inflator can be abutted against the protrusion only when the inflator is oscillated in a direction perpendicular to an axial direction thereof upon operation. Also, according to the knee protection airbag apparatus, the protruding piece is configured to press the end surface of the connection port portion side of the inflator even if the inflator is inclined to cause the end of the connection port portion side to be away from the protruding piece. Namely, in the knee protection airbag apparatus, because the end of the connection port portion side of the inflator is not positioned relative to the case in a vehicle-mounted state, it is inevitable that upon operation the inflator is inclined along the axial direction, and also it is necessary that the protruding piece is set to have a large size to some extent, thereby pressing the end surface of the inflator even in such an inclined state.